Polylactic acid, a sustainable, biocompatible, transparent substrate material for Organ-On-Chip and Microfluidic applications

Organ-on-chips are miniaturised devices aiming at replacing animal models for drug and toxicity studies and studies of complex biological phenomena. The field of Organ-On-Chip has grown exponentially, and has led to the formation of companies providing commercial Organ-On-Chip devices. Yet, it may be surprising to learn that the majority of these commercial devices are made from PDMS, a material widely used in microfluidic prototyping, but which has proven difficult to use in industrial settings and poses a number of challenges to experimentalists, including loss of small compounds. To alleviate these problems, we propose a new substrate for organ-on-chip devices: Polylactic Acid (PLA). PLA is a material derived from renewable resources, and compatible with high volume production such as microinjection moulding. The polymer can be formed into sheets and prototyped into the desired devices in the research lab. The aim of this paper is to assess and prove the suitability of Polylactic acid as substrate material for Organ-on-a-chip applications. Surface properties, biocompatibility, small molecules adsorption and optical properties of PLA are investigated and compared with PDMS and other reference polymers.